diff --git a/doc/ChangeLog b/doc/ChangeLog
index d90fcbd460..cd722bbacc 100644
--- a/doc/ChangeLog
+++ b/doc/ChangeLog
@@ -1,8 +1,68 @@
+===============================================================
+
+Tag name: cam6_4_194
+Originator(s): jimmielin
+Date: Aug 7, 2026
+One-line Summary: Fix CLUBB pbuf initialization
+Github PR URL: https://github.com/ESCOMP/CAM/pull/1639
+
+Purpose of changes (include the issue number and title text for each relevant GitHub issue):
+- Closes #1638 - Crash in ERP_D_Ln9.ne30pg3_ne30pg3_mt232.F1850C_MTso.derecho_intel.cam-outfrq9s after CESM alpha09b
+
+Describe any changes made to build system: N/A
+
+Describe any changes made to the namelist: N/A
+
+List any changes to the defaults for the boundary datasets: N/A
+
+Describe any substantial timing or memory changes: N/A
+
+Code reviewed by: cacraig
+
+List all files eliminated: N/A
+
+List all files added and what they do: N/A
+
+List all existing files that have been modified, and describe the changes:
+M       src/physics/cam/clubb_intr.F90
+  - move physpkg-level pbuf field initialization to always instead of first timestep.
+    this was causing unphysical values to be in the pbuf when restarting the model causing
+    a crash in the gw code which was computing upwp_clubb**2+vpwp_clubb**2
+
+If there were any failures reported from running test_driver.sh on any test
+platform, and checkin with these failures has been OK'd by the gatekeeper,
+then copy the lines from the td.*.status files for the failed tests to the
+appropriate machine below.  All failed tests must be justified.
+
+derecho/intel/aux_cam:
+  ERP_D_Ln9.ne30pg3_ne30pg3_mt232.F1850C_MTso.derecho_intel.cam-outfrq9s (Overall: DIFF) details:
+    - baseline was missing since the test started to crash in cam6_4_193 after the externals update.
+    - manually comparing against the baseline in cam6_4_192 showed expected answer differences due to
+      updated externals.
+
+  SMS_D_Ln9_P1536x1.ne0CONUSne30x8_ne0CONUSne30x8_mt12.FCHIST.derecho_intel.cam-outfrq9s (Overall: DIFF) details:
+    FAIL SMS_D_Ln9_P1536x1.ne0CONUSne30x8_ne0CONUSne30x8_mt12.FCHIST.derecho_intel.cam-outfrq9s BASELINE
+         /glade/campaign/cesm/community/amwg/cam_baselines/cam6_4_193_intel: ERROR BFAIL some baseline files were missing
+    - baseline was missing since cam6_4_193 ran into the intermittent failure:
+      intermittent failure in CTSM code (lnd_set_decomp_and_domain.F90)
+
+derecho/nvhpc/aux_cam:
+  ERS_Ln9.ne30pg3_ne30pg3_mt232.FHISTC_LTso.derecho_nvhpc.cam-outfrq9s_gpu_default (Overall: FAIL) details:
+    FAIL ERS_Ln9.ne30pg3_ne30pg3_mt232.FHISTC_LTso.derecho_nvhpc.cam-outfrq9s_gpu_default MODEL_BUILD
+    - pre-existing failure from cam6_4_193 previously reported via email.
+
+izumi/nag/aux_cam:
+  ERC_D_Ln9.f10_f10_mt232.FHIST_C5.izumi_nag.cam-outfrq3s_subcol (Overall: FAIL) details:
+    FAIL ERC_D_Ln9.f10_f10_mt232.FHIST_C5.izumi_nag.cam-outfrq3s_subcol COMPARE_base_rest
+    - pre-existing failure -- see https://github.com/ESCOMP/CAM/issues/1514
+
+izumi/gnu/aux_cam: All PASS
 
 ===============================================================
 
+
 Tag name: cam6_4_193
-Originator(s):cacraigucar
+Originator(s): cacraigucar
 Date: August 6, 2026
 One-line Summary: Update externals to match cesm3_0_beta09
 Github PR URL: https://github.com/ESCOMP/CAM/pull/1637
diff --git a/src/physics/cam/clubb_intr.F90 b/src/physics/cam/clubb_intr.F90
index c9b05212be..0620c89a40 100644
--- a/src/physics/cam/clubb_intr.F90
+++ b/src/physics/cam/clubb_intr.F90
@@ -2026,22 +2026,21 @@ subroutine clubb_ini_cam(pbuf_ini)
        call pbuf_set_field(pbuf_ini, pdf_zm_varnce_w_2_idx, 0.0_r8)
        call pbuf_set_field(pbuf_ini, pdf_zm_mixt_frac_idx,  0.0_r8)
 
-       call pbuf_set_field(pbuf_ini,  ttend_clubb_idx,      0.0_r8)
-       call pbuf_set_field(pbuf_ini,  upwp_clubb_gw_idx,    0.0_r8)
-       call pbuf_set_field(pbuf_ini,  vpwp_clubb_gw_idx,    0.0_r8)
-       call pbuf_set_field(pbuf_ini,  thlp2_clubb_gw_idx,   0.0_r8)
-       call pbuf_set_field(pbuf_ini,  wpthlp_clubb_gw_idx,  0.0_r8)
-
-       call pbuf_set_field(pbuf_ini,  ttend_clubb_mc_idx,     0.0_r8)
-       call pbuf_set_field(pbuf_ini,  upwp_clubb_gw_mc_idx,   0.0_r8)
-       call pbuf_set_field(pbuf_ini,  vpwp_clubb_gw_mc_idx,   0.0_r8)
-       call pbuf_set_field(pbuf_ini,  thlp2_clubb_gw_mc_idx,  0.0_r8)
-       call pbuf_set_field(pbuf_ini,  wpthlp_clubb_gw_mc_idx, 0.0_r8)
-
     endif
 
     ! The following is physpkg, so it needs to be initialized every time
-    call pbuf_set_field(pbuf_ini, fice_idx,    0.0_r8)
+    call pbuf_set_field(pbuf_ini,  fice_idx,               0.0_r8)
+    call pbuf_set_field(pbuf_ini,  ttend_clubb_idx,        0.0_r8)
+    call pbuf_set_field(pbuf_ini,  upwp_clubb_gw_idx,      0.0_r8)
+    call pbuf_set_field(pbuf_ini,  vpwp_clubb_gw_idx,      0.0_r8)
+    call pbuf_set_field(pbuf_ini,  thlp2_clubb_gw_idx,     0.0_r8)
+    call pbuf_set_field(pbuf_ini,  wpthlp_clubb_gw_idx,    0.0_r8)
+
+    call pbuf_set_field(pbuf_ini,  ttend_clubb_mc_idx,     0.0_r8)
+    call pbuf_set_field(pbuf_ini,  upwp_clubb_gw_mc_idx,   0.0_r8)
+    call pbuf_set_field(pbuf_ini,  vpwp_clubb_gw_mc_idx,   0.0_r8)
+    call pbuf_set_field(pbuf_ini,  thlp2_clubb_gw_mc_idx,  0.0_r8)
+    call pbuf_set_field(pbuf_ini,  wpthlp_clubb_gw_mc_idx, 0.0_r8)
 
     ! --------------- !
     ! End             !